In turbomachines such as stationary gas turbines or aircraft engines, it is necessary to create an equalization for the great difference in thermal growth of the components due to high temperature differences between components and component sections near the hot gas and components and component sections near the housing.
Exemplary components include turbine rings, which are usually situated on the housing and delimit a tip gap to opposing moving blade tips. Turbine rings of an integral design are usually spoke-centered, in that they are supported in radial guides on the housing and are thus able to expand freely when heated. However, it has been found that the great radial expansion of the turbine rings differ significantly from the behavior of the rotors during heating, so the tip gap becomes greater and thus turbine efficiency worsens. From a cost standpoint, however, manufacturing of the integral turbine rings is advantageous because of the reduced number of parts.
Equalization of thermal growth in segmented turbine rings is usually ensured by circumferential gaps. The turbine rings are fastened onto the housing but are able to expand freely in the circumferential direction. A radial expansion imposed on the turbine rings by the housing corresponds more to the behavior of the rotors, so that a smaller tip gap and consequently a better efficiency are achieved. To prevent leakage gaps between neighboring ring segments, their butt joints must be sealed. However, the plurality of ring segments as well as the seals increase the manufacturing complexity and thus also increase the manufacturing costs.